基于兔成体心房肌细胞可逆性永生化的Tbx18治疗SSS的基因修饰策略的研究

生物起搏取代人工起搏器是病态窦房结综合征（SSS）治疗的发展方向。生物起搏是指利用生物学技术，修复或重建心脏起搏中心，使心脏恢复自然的生理性起搏。目前相关研究主要集中在两个方面：基因治疗和细胞移植。鉴于心脏起搏传导系统特殊的电生理特性，我们认为SSS非常适用于基因治疗，设想通过合理的基因修饰，使在体少量心房肌细胞产生稳定的起搏性能，替代窦房结激动整个心脏的工作。我们拟通过表达两侧带有LoxP位点的SV40 T基因的逆转录病毒建立便于体外培养和研究的可逆性永生化兔成体心房肌细胞系。然后用腺病毒、慢病毒和pMPB系统为载体进行平行转染实验，以Txb18为主选目的基因导入成体心房肌细胞，观察比较其诱导成体心房肌细胞转分化为起搏细胞的效率、稳定性和安全性，从而选择最优的基因修饰策略，最后对兔SSS模型进行在体基因治疗，观察其重建生物起搏的效果。从而为SSS的生物起搏治疗提供新的理论依据。

Biological pacemaking is hoped to replace artificial pacemaker, become a new treatment of Sick sinus syndrome(SSS ) in future. Biological pacemaking is refers to using biological technology to repair or reconstruct cardiac pacing center, restore the natural physiological pacing of heart . The current research mainly focuses on two aspects: gene therapy and cell transplantation. In view of the special electrophysiological properties of cardiac pacing conduction system, we believe that SSS is really suitable for gene therapy. We conceive to transform a small number of atrial myocytes into pace making cells by using specific genetic modification in vivo, generate a substitute for the sinoatrial node to fire the heart work. First of all, we are going to set up a reversibility immortalized rabbit adult atrial myocyte cell line via retrovirus which express SV40 T gene between two LoxP sites. Then several parallel experiments will be performed ,using adenovirus, slow virus and pMPB system as carrier respectively, Txb18 as main target gene to induce adult atrial muscle cells trasform into pace making cells. A superior gene modification strategy will be defined after the compare of the efficiency, stability and safety of different induction gene treatment strategies. Finally use this gene modification strategy on rabbit SSS model to observe and evaluate the effect of reconstruction of biological pacemaking.Our study will provide some novel theoretical basis for the SSS biological pacing therapy.